import os import select import socket import threading import ujson from ipc_unix.utils import DEFAULT_SOCKET_READ_TIMEOUT, read_payload, socket_has_data class Subscriber: def __init__(self, socket_path): self.socket_path = socket_path self.socket = socket.socket( socket.AF_UNIX, type=socket.SOCK_STREAM | socket.SOCK_NONBLOCK ) self.socket.connect(self.socket_path) @property def has_data(self): return socket_has_data(self.socket) def listen(self): while True: yield from self.get_message() def get_messages(self) -> dict: return read_payload(self.socket) def flush_data(self): while self.has_data: yield from self.get_messages() def get_latest_message(self): data = list(self.flush_data()) return data[-1] if data else None def close(self): self.socket.close() class Publisher: def __init__(self, socket_path): self.socket_path = socket_path self.master_socket = socket.socket( socket.AF_UNIX, type=socket.SOCK_STREAM | socket.SOCK_NONBLOCK ) self.master_socket.bind(self.socket_path) self.master_socket.listen() self.connections = [] self.accepting_new_connections = threading.Event() self.accepting_new_connections.set() self.new_connections_thread = threading.Thread( target=self._accept_new_connections ) def start(self): self.accepting_new_connections.set() self.new_connections_thread.start() def close(self): self.accepting_new_connections.clear() if self.new_connections_thread.is_alive(): self.new_connections_thread.join() self.master_socket.close() for connection in self.connections: connection.close() self.connections.clear() os.remove(self.socket_path) def accept_outstanding_connections(self): if self.new_connections_thread.is_alive(): raise Exception( "Cannot accept connections manually whilst thread is running" ) while socket_has_data(self.master_socket): new_socket, _ = self.master_socket.accept() self.connections.append(new_socket) def _accept_new_connections(self): while self.accepting_new_connections.is_set(): if socket_has_data(self.master_socket): new_socket, _ = self.master_socket.accept() self.connections.append(new_socket) def write(self, message: dict): _, writable, errorable = select.select( [], self.connections, [], DEFAULT_SOCKET_READ_TIMEOUT * len(self.connections), ) dead_sockets = [] if writable: data = ujson.dumps(message).encode() + b"\n" for sock in writable: try: sock.send(data) except BrokenPipeError: dead_sockets.append(sock) for sock in dead_sockets: if sock in self.connections: self.connections.remove(sock) sock.close()